Regular season totals, playoffs not included

Revised as of 8/31/2012

Running backs are ranked according to DYAR, or
Defense-adjusted Yards Above Replacement. This gives the value of the
performance on plays where this RB carried/caught the ball compared to replacement level, adjusted for situation
and opponent and then translated into yardage. DYAR
(and its cousin, YAR, which isn't adjusted based on opponent) is further explained here.

The next statistic given is DVOA, or Defense-adjusted Value Over Average. This number represents
value, per play, over an average running back in the same game
situations. The more positive the DVOA rating, the better the player's
performance. Negative DVOA represents below-average offense. DVOA (and its cousin, VOA, which isn't adjusted based on
opponent) is further explained
here.

The simple version: DYAR means a running back with more total value. DVOA means a running back with more value per play.

Effective Yards, listed in red, translate DVOA into a yards per
attempt figure. This provides an easy comparison: in general, players
with more Effective Yards than standard yards played better than standard
stats would otherwise indicate, while players with fewer Effective Yards
than standard yards played worse than standard stats would otherwise
indicate. Effective Yards are not the best way to measure total value
because they are more dependent on usage than DYAR.

The final statistic is Success Rate. This number represents the player's consistency, measured by successful running plays (the definition of success being different based on down and distance) divided by total running
plays. A player with higher DVOA and a low success rate mixes long runs
with downs getting stuffed at the line of scrimmage. A player with lower
DVOA and a high success rate generally gets the yards needed, but doesn't often
get more. Success Rate is further explained here.
It is not adjusted for opponent.

These numbers do not separate the performance of a running back from the performance of his offensive line. (You'll find numbers that try to do that on this page.) Be aware that one will affect the other.

All fumbles are considered equal, whether recovered by the offense or defense.

Clicking on a player's name will bring you to his FO player page with advanced stats through the most recent season.